To answer this question, the user needs to have some knowledge about the characters in the Indian epic Mahabharata.
Option A: Arjuna is one of the main characters in the Mahabharata, but he is not called Dharmaputra. He is known for his archery skills and is the third of the five Pandava brothers.
Option B: This option is correct. Yudhishtira, the eldest of the Pandava brothers, is often referred to as Dharmaputra. He is known for his adherence to dharma, or righteousness, and is respected for his wisdom and sense of justice.
Option C: Bheeshma is an important character in the Mahabharata, but he is not called Dharmaputra. He is a skilled warrior and is respected for his knowledge and wisdom.
Option D: Duryodhana is one of the main antagonists in the Mahabharata and is not called Dharmaputra. He is known for his jealousy and greed, which ultimately lead to the Kurukshetra War.
Therefore, the answer is:
The Answer is: B. Yudhishtira